The people at Bungie are famous for putting obscure Easter Eggs into their games. Halo's creators have packed the massive sci-fi shooter franchise with all sorts of references and secrets, and fans love finding them.

A tipster—who asked that we not use his name—pointed us to an Easter Egg in the special edition of Halo: Reach that we believe nobody has discovered yet. While it's possible that someone somewhere has stumbled upon it, of course, we couldn't find anyone talking about it on the web anywhere.

Halo spoilers follow.

The limited edition of Halo: Reach, released in 2010, came with an ID card for scientist Catherine Halsey, an important character in the world of Halo and the creator of the AI bot Cortana. While some people noticed that something was up with the image on the card, nobody noticed one strange secret: if you take a blacklight to it, you can see a strange photo that's sort of half-Halsey, half-Cortana that looks like a blue, Cortana-ish version of Halsey.

Here's the card:

Now take a blacklight to it and...

Blue Halsey! Looks like Cortana! Cool, right? We'll forgive you for not finding this one, because really, who owns a blacklight?